1. Field of the Invention
The present invention relates to a hand mechanism of a library apparatus which contains magnetic tape cartridges or the like, and the hand mechanism is used for extracting the cartridge.
This application is based on patent application Ser. No. Hei 11-72707 filed in Japan, the contents of which are incorporated herein by reference.
2. Description of the Related Art
Conventional magnetic tape library apparatuses comprise (i) an ENTRY/EXIT mechanism (i.e., storage shelf) in which a plurality of cells are vertically stacked, and (ii) a hand mechanism for extracting a cartridge stored in one of the cells. When an operator stores a cartridge in the ENTRY/EXIT mechanism, the hand mechanism detects the cartridge and extracts the cartridge from the ENTRY/EXIT mechanism, and transfers it to a predetermined area.
More specifically, a specific bar code is assigned to each cartridge so as to identify the cartridge, and the hand mechanism has a bar code reader. The hand mechanism is positioned so as to make the hand face the bar code of a target cartridge, and the bar code is read by the bar code reader. After the reading operation, the picker of the hand mechanism is moved forward so as to grasp and extract the cartridge and to transfer the cartridge to a predetermined area according to the bar code information.
In order to accurately read the bar code, it is necessary to slide the bar code reader on the scan lines of the bar code; thus, a device for sliding the bar code reader itself or the hand mechanism (to which the bar code reader is attached) is necessary, and the manufacturing cost is higher. In addition, after the bar code is read out by sliding the bar code reader or the hand mechanism, the picker is moved forward so as to grasp the cartridge. Therefore, it is impossible to perform a high-speed operation.
Another type of the hand mechanism has been developed, which has a slip-out preventing mechanism for preventing the grasped cartridge from slipping out from the hand. In this type of hand mechanism, when the cartridge is grasped and drawn in, the slip-out preventing mechanism is rotated so as to open a path where the picker proceeds, and after the cartridge is drawn in, the slip-out preventing mechanism is again rotated so as to shut the above path and to hold the cartridge. In this case, the bar code reader must be provided or attached outside the area where the slip-out preventing mechanism can rotate, so as not to prevent the slip-out preventing mechanism from rotating. Accordingly, the size of the hand mechanism must be relatively large.
In consideration of the above circumstances, an objective of the present invention is to provide a library apparatus having a smaller hand mechanism and realizing highly accurate and high-speed identification-data (typically, bar code) reading.
Therefore, the present invention provides a hand mechanism of a library apparatus for extracting a cartridge stored in a storage shelf, comprising:
a picker for grasping the cartridge, which is movable along a predetermined path in the frontward and rearward directions so as to proceed towards the storage shelf and move back from the shelf;
a plate portion which is rotatable so as to make the plate portion more distant from or closer to the predetermined path of the picker; and
a read-out section attached to the plate portion, for reading out identification data provided to the cartridge, and
wherein when the picker proceeds towards the storage shelf, the plate portion is rotated so as to make the plate portion, and the attached read-out section more distant from the predetermined path of the picker.
According to the above hand mechanism, the read-out section and the plate portion are integrally provided; thus, the read-out section is also rotated according to the rotation of the plate portion. Therefore, the rotation of the plate portion is not limited by the read-out section, and it is unnecessary to provide or arrange the read-out section outside the rotatable area of the plate portion. Accordingly, a smaller hand mechanism can be realized.
Preferably, when the picker proceeds towards the storage shelf, the plate portion is rotated upward. In a typical example, when the picker proceeds towards the storage shelf, the picker pushes up the plate portion and the attached read-out section.
In particular, if the read-out section is a bar code reader, when the bar code reader rotates together with the plate portion, the scanning beam can slide without sliding the bar code reader itself. Therefore, a mechanism for sliding the bar code reader is unnecessary, and the target bar code can be accurately read out with high speed.